JacksonMapUtils.java

JacksonMapUtils.java

import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
import org.springframework.util.ReflectionUtils;

import java.beans.PropertyDescriptor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

public class JacksonMapUtils {

    /**
     * Get map of a flat xml java bean using JacksonXmlProperty annotations
     * <p> Notice: Null values will be ignored </p>
     */
    public static <T> Map<String, String> getMapOfFlatXmlBean(Class<T> clz, T obj) {
        Map<String, String> res = new HashMap<>();
        ReflectionUtils.doWithFields(clz, (field -> {
            String val = getFieldValue(clz, field, obj);
            if (val != null) {
                res.put(getXmlFieldKey(field), val);
            }
        }));
        return res;
    }

    private static String getXmlFieldKey(Field field) {
        String xmlFieldKey = field.getName();
        JacksonXmlProperty jacksonXmlProperty = field.getAnnotation(JacksonXmlProperty.class);
        if (jacksonXmlProperty != null && jacksonXmlProperty.localName().length() > 0) {
            xmlFieldKey = jacksonXmlProperty.localName();
        }
        return xmlFieldKey;
    }

    private static String getFieldValue(Class<?> clz, Field field, Object obj) {
        String fieldName = field.getName();
        try {
            PropertyDescriptor pd = new PropertyDescriptor(fieldName, clz);
            Method getter = pd.getReadMethod();
            Object val = getter.invoke(obj);
            if (val == null) {
                return null;
            }
            return val.toString();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}